The present invention relates to a conveyor system.
Various conveyor systems by means of which passengers or goods can be transported from a first height level to a second height level are known from the prior art. Elevators or cranes have a purely vertical path of travel. Mountain railways such as e.g. cog railways, on the other hand, also cover a significant horizontal distance when overcoming a height difference. Both purely vertical paths of travel and paths of travel which have a finite gradient in order to overcome a height difference, but whose primary objective is to overcome said height difference, are classed in this application under the term ‘substantially vertical path of travel’.
Most of the conveyor systems referred to are nowadays fitted with a rotationally operating electric motor and a cable traction system by means of which the rotational motion of the electric motor can be converted into a translational motion of the corresponding transport device. Such systems are relatively complicated to construct and bulky.
DE 10 2005 017 500 A1, on the other hand, discloses a passenger conveyor system comprising a synchronous linear motor. In order to make the design of such a passenger conveyor system simpler and cheaper, it is proposed here that, to drive it, the passenger conveyor system be equipped with a synchronous linear motor with a rack-and-pinion-type permanent-magnet-free secondary part, the primary part of the synchronous linear motor being fastened to the transport device, in or on which persons can be conveyed. The primary part comprises coils and permanent magnets for generating magnetic fields which interact with one another in order to drive the linear motor and thus the transport device. The secondary part is permanent-magnet-free and consequently highly resistant to soiling. A linear motor of this kind is for system-related reasons embodied as a short-stator motor, the term stator in a linear motor referring here and throughout the application to an element which can be supplied with an armature current, irrespective of whether the stator moves or stands still. A linear motor of this type is significantly cheaper than normal linear motors in which permanent magnets are arranged in the secondary part. This cost advantage is particularly noticeable in long paths of travel which require a secondary part of much greater length.
Due to the fact that the cable drives which are needed in rotational systems are not necessary in linear-motor-driven conveyor systems, there is inevitably also no need here for the operational and safety braking devices which are in part coupled to such cable drives.
The object of the invention is therefore to increase the operational safety of a conveyor system driven by means of a linear motor.